1. Preheat the oven to 350 degrees F. Grease a 9" x 9" baking pan.
2. In a bowl, thoroughly combine all dry ingredients (flour, sugar, cocoa powder, baking soda, and salt). In another bowl, combine all wet ingredients (oil, water, and vanilla extract). Add WET ingredients to the DRY (should be creamy & pretty smooth). Stir in margarine. (Use 1 cup margarine for more fudgey brownies and 3/4 cup margarine for more cakey brownies).
3. Pour into a baking pan (brownie mixture should not be too thick) and add chocolate chips and walnuts.
4. Bake in oven for 20 to 30 minutes (the less minutes, the more moist). After about 5 to 10 minutes the mixture might look airy and bubble, but that's okay. Cut out a small piece from the corner and and taste to check if the brownies are done to your liking. When fully baked, the top of the brownies should be slightly cracked in appearance.
5. Chill in the fridge for 10 minutes before cutting it into squares or else the brownies will fall apart. Enjoy!
Source of recipe: A mix of many different brownie recipes